1. Field of the Invention
The present invention relates generally to spindle-type cotton harvesters and, more specifically, to a scrapping plate for forcing cotton into the spindles.
2. Related Art
Cotton harvesters include rotating spindles which project into the plant row and remove cotton from the plants. The rearward velocity of the spindles is synchronized with the forward speed of harvester to generally provide zero relative velocity between the spindles and the cotton plants while the spindles project into the plants. To help assure contact with cotton bolls intermediate adjacent spindles, scrapping plates are placed adjacent the spindles in the picking zone to slow the intermediate bolls and force them into contact with the next spindles. With such plates, typical picking efficiency is in a range from approximately 97 to 98 percent. Increasing efficiency beyond that range has been a continuing source of difficulty. There is a need to better assure that the intermediate bolls are forced into contact with the spindles so those bolls are not left on the plant and picking efficiency is increased. The efficiency must be increased without inhibiting plant movement through the picking zone so that harvest speed can be maintained for good machine productivity.
It is therefore an object of the present invention to provide an improved scrapping plate for a cotton harvester. It is a further object to provide such a plate which overcomes the aforementioned problems.
It is another object to provide an improved cotton harvester scrapping plate which increases picking efficiency over at least most previously available scrapping plates. It is yet a further object to provide such a plate which does not significantly inhibit plant movement through the harvest zone so that machine productivity can be maintained or improved.
It is a further object of the invention to provide an improved scrapping plate which maintains the cotton in the picking zone longer for improved picking efficiency. It is yet another object to provide such a plate which includes ribs with a taper that helps to wedge and slow intermediate cotton bolls.
Accordingly, a scrapping plate constructed in accordance with the teachings of the present invention includes channel areas with tapered or narrowing structure to provide better contact between the spindles and cotton. In one embodiment, the rear or trailing portion of the scrapping plate incorporates an angle in the bottom profile which forces cotton into the spindle before being released. The scrapping plate ribs which are spaced vertically from each other and located between adjacent rows of spindles are tapered so that rib surfaces are generally parallel to the spindle tapered surfaces in the picking zone. The parallel arrangement places cotton equidistant from the spindle along the length of the picking zone.
In other various aspects of the invention, the ribs can be tapered in the fore-and-aft direction to better hold the intermediate cotton bolls in the scrapping plate for a period of time sufficient for the cotton to be picked by the trailing spindle. To provide better entry of the cotton into the area between the scrapping plate ribs, the forward portion of alternating ribs can be terminated rearwardly of the leading portion of the plate. The wider opening at the leading portion of the plate allows the cotton bolls to gather more easily into the depth of the pockets formed between the ribs before the dividing ribs open the bolls and bring the cotton closer to the spindles.